Lost Communication With Restraints Occupant Classification System Module
What it means
U0154 means the restraints system has lost communication with the occupant classification module — the unit under the passenger seat that senses whether an adult, child, or nobody is seated and tells the system whether to arm the passenger airbag. The car still drives, but the airbag light comes on and the passenger airbag may arm or disarm incorrectly, so it's a genuine safety fault. Typical causes are damaged seat wiring or connectors, a power/ground fault, or a failed module.
Can I keep driving? Drivable, but a safety concern — the passenger airbag on/off decision depends on this module, so the airbag light will be on and passenger restraint behavior may be wrong.
Common symptoms
What you'll notice
- Airbag/SRS warning light on
- Passenger airbag on/off indicator wrong or unlit
- Passenger airbag may stay disabled (or fail to disable for a child seat)
- Restraints control module reports lost communication with the occupant classification module
Common causes
Most likely first
- Damaged or corroded connector/wiring under the passenger seatLikely
- No power or ground to the occupant classification moduleCommon
- Seat wiring harness damaged by seat movement or spillsCommon
- Internally failed occupant classification moduleLess often
How to diagnose & fix
Work through it in order
- Scan the restraints system and confirm the occupant classification module is not communicating.
- Inspect the wiring and connector under the passenger seat for damage, corrosion, and unseated pins.
- Check power and ground to the module.
- Repair the seat harness or connector; recalibrate/zero the system if the procedure requires it.
- If it still won't communicate, replace the module per the service procedure, then clear and re-test.
FAQ
Quick answers
Is it safe to drive with U0154?+
Can I just clear U0154?+
Related codes
Often seen with U0154
Read & clear U0154 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.